This invention relates to seat assemblies including vehicle seats and systems for rotating same.
It is often desirable to have a vehicle seat which, during vehicle movement, is positioned in a forwardly-directed, home position within the vehicle and, during occupant ingress or egress, is positioned in a side position rotated approximately 45xc2x0-90xc2x0 from the home position so that the occupant can easily enter or exit the vehicle.
A swivel mechanism or system for such a vehicle seat, however, must be capable of handling the various reactions and stresses which such a swivel mechanism will encounter when the seat includes integrated passenger restraints which are oftentimes provided with current vehicle seats. Such restraints typically include shoulder and lap belts.
The following U.S. patents are related to such swivel mechanisms for vehicle seats: U.S. Pat. Nos. 2,587,679; 2,992,852; 3,051,522; 3,104,911; 4,436,270; 4,792,188; 4,802,706; 5,000,505; 5,474,353; 5,524,952; 5,540,482; 5,634,537; 5,651,576; and 5,720,462.
An object of the present invention is to provide a seat assembly including a vehicle seat and system for rotating same wherein the system for rotating the vehicle seat is relatively compact yet strong enough to carry integrated seat restraint loads.
In carrying out the above object and other objects of the present invention, a seat assembly including a vehicle seat is provided. The assembly also includes a base having a lower base section and an upper base section which supports the vehicle seat. The assembly further includes an actuator having an output shaft mounted on the lower base section and a bearing assembly for rotatably supporting the upper base section on the lower base section. The assembly also includes a transmission for mechanically coupling the output shaft of the actuator to the upper base section. The upper base section rotates about a substantially vertical axis relative to the lower base section between a forwardly-directed home position and a side position of the vehicle seat upon actuation of the actuator.
Preferably, the transmission includes a drive screw rotatably supported on the lower base section in driving engagement with the output shaft of the actuator to rotate about a substantially horizontal axis upon actuation of the actuator.
Also, preferably, the transmission includes a drive nut threadedly mounted on the drive screw to move along the substantially horizontal axis upon actuation of the actuator.
The transmission further includes a flexible cable for coupling the output shaft of the actuator to the drive screw.
Preferably, the transmission includes a link coupled to the upper base section and the drive nut to transmit linear motion of the drive nut to rotary motion of the upper base section.
Preferably, the actuator is an electromagnetic actuator such as a reversible DC motor.
Also, preferably, the bearing assembly includes a plurality of thrust bearings and the lower base section includes a tongue portion clamped between the thrust bearings.
Preferably, the tongue portion is integrally formed with the lower base section.
Also, preferably, the lower base section is a metal plate wherein the tongue portion is an annular tongue portion integrally formed with the metal plate.
Still, preferably, the upper base section is a metal plate having an upper surface and wherein the vehicle seat is supported on the upper surface thereof.
Still further in carrying out the above object and other objects of the present invention, a system for rotating a vehicle seat is provided as described above.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.